Galvanometer.



W. H. APTHORPE.

GALVANONIETER.

APPLICATION FILED AUG. I4', |914.

1,@1 9,61?, Patented Mar.20,1917.

3 SHEETS-SHEET I W. H. APTHORPE.

GALVANOIVIETER. APPLICATION FILED AUG. I4, i914.

1,219,61?. Patented Mr.20,1917.

3 SHEETS-SHEET 3.

Gwvmm K @WM U TED STATES NPa N f curro,

WILLIAM HERBERT APTHORPE, F CAMBRIDGE, ENGLAND, ASSIGNOR T0 TAYLOR INSTRUMENT COMPANIES, ROCHESTER, NEW YORK, A CORPORATION 0F NEW GALVAN OMETER.

Specification of Lett-ers Patent.

Patented Mar. 20, 1917.

, clear, 'and eXact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked thereon.

My invention relates to galvanometers and similar instruments of the type in which a conducting fiber is maintained in a magnetic or electrostatic field and its movements observed or recorded when a current' passes therethrough. Such instruments are employed for measuring small currents, as fpr instance those generated by muscular movements, or for receiving wireless mes' sages, and the present inventionhas for its object to afford a construction whereby two or more Sbers may be arranged in the mag-l m the same or independent elec-- netic {iel tric circuits, in such a manner that they may be adjusted relatively to each other to bring them both to a position within the field of vision of the optical system by which they are observed. A further purpose of the invention is toprovide the optical system referred to with means for bringing the images of the fibers suiiiciently close for photographic impression or observation. To these and other ends the invention consists in certain improvements and combinations of parts, all as will be hereinafter -more fully described, the novel features being pointed out in the claim at the end of the specification.

In the drawings: Figurel is a plan view of a galvanometer equipped with a preferred embodiment of my invention;

iFig. 2 isa side elevation;

Fig. 3 is an enlarged view of the fiber supporting devices;

Fig. 4 is a side view of the same;

Fig. 5 is a sectional view on theline a-a of Fig. 4; j j

Fig. 6 is an end elevatlon of the attach-l ment for the-optical system to effect adjustment of the images of the fibers;

Fig. 7 is a side elevation of the same, and

Fig. 8 is a diagrammatic view showing the position of the fibers with relation to the optical system.

Similar reference characters in the several figures indicate the same parts.

In the embodiment shown A designates an electro-magnet of which B are the poles, the fibers being suspended between the latter, as will be described presently. The fibers are designated at C and C, being arranged in the casing D, which is provided with an opening ai through which the fibers are visible. The fibers are mounted so that the tension of each can be adjusted independently of the other, and to this end the ber C is supported between clamps 0 and c while the fiber C is supported between the clamps c2 and c3. The clamps c and c2 are each mounted on a pin o4, which is slidably mounted in the holder and actuated upwardly by means of a spring c5 arranged between a shoulder c6 and the enlarged head c?. The pin c* carries at its upper end a projection cs which engages the short arm 09 of a lever 01. The latter is pivoted at c and is adjustable to change the tension of the fiber by means of a set-screw 012 which isY operated to change the position of the leverl 01 by engagement with the long arm of the latter.` When the set-screw is operated to depress the short arm c", the tension on the fiber is decreased, while adjustment in the opposite direction releases the spring cs correspondingly, and permits it to lift the pin 04, and thus increase thetension of the fiber. 013 designates a nut which limits the degree of tension to which the fiber can be subjected.

The holderwlhich supports the fiber retaining clamps is designated generally at E, being -suspended on the poles of the magnet from three points and adjustable with relation thereto. To this end, the holder carries a pair of adjustable legs F, F, which engage coperating sockets on the magnet poles. The holder also carries an arm or'bracket g engaging a stop g and held thereagainst by the spring g2, which is arranged between the arm or bracket and the head of an adjustable screw g3. B adjusting the legs F and F just describe the holder can be moved 'until one of the fibers is brought properly into trically on a post h, which is mounted tov turn in a bracket h. The post carries a transversely arranged pin h2 which extends beyond the opposite sides thereof through an enlarged opening in the bracket 7L. One end of the pin 11,2 engages an adjustable setscrevv h3 While the opposite end is connected to a spring z* which in turn is secured to the bracket. It will be seen that by turning the set-screw h3 the clamp Will be turned correspondingly through a slight angle causing the fiber to be adjusted in a lateral direction. The clamps c and o3 are mounted on insulating blocks and connected with the terminals i195 and h6. The clamp c forms a circuit with the holder, which carries the terminal if, While its designates the terminal to Which the clamp 02 is connected, the latter being insulated from the holder.

In order to bring the ima-ges of the bers into closer relation for observing or photographing them, I may provide a pair of prisms, which are suitably arranged with relation to the optical axis so as to divert the rays. To this end I employ a clamp k which is conveniently attached to the Web a of the frame of the instrument and carries a holder 7c to Which is secured a split tube 162. Slidably arranged Within the tube is a rod 7a3 which carries at its outer end a sleeve ai'in Which turns a pin 705. The pin 705 carries a frame k6 Within which theprisms and y are mounted, they being held in proper relation by the spring 107. Fig. 8 shows diagrammatically the position of the prisms With relation to the microscope lens 2, and by the construction last described, the prisms m, y can be brought into proper position before the lens by sliding the rod 7c3 and by turning the pin h5 so that the rays shown in dotted lines will be diverted, and the images Z, Z of the fibers C C brought close together when they' are projected onto the plate.

I claim as my invention:

In a galvanoineter, the combination with a plurality of fibers mounted in a magnetic' field, of supporting means for the fibers including clamps that are adjustable to change the relative position of the fibers and means for adjusting the tension ofthe fibers independently of each other.

WILLIAM t HERBERT APTHORPE.

Witnesses WALTER I. SKERTEN, KENNETH L. STEWARD. 

